An alarm filter circuit used in telecommunication systems for interconnecting between incoming telephone lines and alarm unit located at a subscriber=s premises so as to block DSL data signals to and from the alarm unit for preventing interference is provided. In one preferred embodiment, the alarm filter circuit includes a first inductor, a second inductor and a third capacitor functioning as a second-order low-pass filter section so as to block the DSL data signals to and from the alarm unit. Second and third capacitors functioning as a first-order high-pass filter section is provided so as to bypass the DSL data signals on the incoming telephone lines to the house wiring. A third inductor and a fourth inductor functioning as a first-order low-pass filter is provided so as to block high-frequency signals between the house wiring and the alarm unit. In a second embodiment, a fourth-order elliptical low-pass filter section replaces the second-order low-pass filter section. In a third embodiment, a third-order high-pass filter section replaces also the first-order high-pass filter section.
Legal claims defining the scope of protection, as filed with the USPTO.
1. An alarm filter circuit used in telecommunication systems for interconnecting between incoming telephone lines and an alarm unit located at a subscriber's premises so as to block DSL data signals to and from the alarm unit for preventing interference, said alarm filter circuit comprising: a second-order low-pass filter section formed of a first inductor, a second inductor, and a first capacitor; the first inductor having a first end and a second end; the second inductor having a first end and a second end; the first capacitor having a first end connected to said first end of said first inductor and to a first output terminal pin and having a second end connected to said first end of said second inductor and to a second output terminal pin; a first-order high-pass filter section formed of second capacitor and a third capacitor; the second capacitor having a first end connected to said second end of said first inductor and to a first input terminal pin and having a second end connected to a second input terminal pin; the third capacitor having its first end connected to said second end of said second inductor and to a third input terminal pin and having its second end connected to a fourth output terminal pin; a first-order low-pass filter section formed of third inductor and a fourth inductor; the third inductor having a first end connected also to said second end of said second capacitor and having a second end connected to a third output terminal pin; and the fourth inductor having a first end connected also to said second end of said third capacitor and having a second end connected to a fourth output terminal pin.
2. An alarm filter circuit as claimed in claim 1 , wherein said first inductor, second inductor and first capacitor function as the second-order low-pass filter section so as to block the DSL data signals to and from said alarm unit.
3. An alarm filter circuit as claimed in claim 2 , wherein said first and second inductors have values on the order of 10 mH.
4. An alarm filter circuit as claimed in claim 3 , wherein said third capacitor has a value on the order of 22 nf.
5. An alarm filter circuit as claimed in claim 4 , wherein said third and fourth inductors function as the first-order low-pass filter section so as to block high-frequency signals to and from house wiring and said alarm unit.
6. An alarm filter circuit as claimed in claim 5 , wherein said third and fourth inductors have values on the order of 4.7 mH.
7. An alarm filter circuit as claimed in claim 6 , wherein said second and third capacitors function as the first-order high-pass filter section so as to bypass the DSL signals on the incoming telephone lines to the house wiring.
8. An alarm filter circuit as claimed in claim 7 , wherein said second and third capacitors have values on the order of 150 nf.
9. An alarm filter circuit as claimed in claim 1 , wherein said first through fourth inductors and first through third capacitors are housed in a modular type adaptor design having plug means on its one end for connection to the incoming telephone lines and having jack means on its other end for connection to said alarm unit.
10. An alarm filter circuit as claimed in claim 9 , wherein said plug means is a RJ-45 plug.
11. An alarm filter circuit as claimed in claim 10 wherein said jack means is a RJ31X jack.
12. An alarm filter circuit as claimed in claim 11 , wherein said adapter design is capable of self-installation by a subscriber or customer.
13. An alarm filter circuit used in telecommunication systems for interconnecting between incoming telephone lines and an alarm unit located at a subscriber's premises so as to block DSL data signals to and from the alarm unit for preventing interference, said alarm filter circuit comprising: a fourth-order elliptical low-pass filter section formed of first through fourth inductors and first through fourth capacitors; the first inductor having a first end and a second end; the second inductor having a first end and a second end; the first capacitor having a first end connected to said first end of said first inductor and having a second end connected to said first end of said second inductor; said third inductor and said second capacitor being connected in parallel and having its one end joined also to said first end of said first inductor and its other end joined to one end of said third capacitor and a first output terminal pin; said fourth inductor and fourth capacitor being connected in parallel and having its one end joined also to said first end of said second inductor and its other end joined to the other end of said fourth capacitor and a second output terminal pin; a first-order high-pass filter section formed of fifth capacitor and a sixth capacitor; the fifth capacitor having a first end connected to said second end of said first inductor and to a first input terminal pin and having a second end connected to a second input terminal pin; the sixth capacitor having its first end connected to said second end of said second inductor and to a third input terminal pin and having its second end connected to a fourth output terminal pin; a first-order low-pass filter section formed of fifth inductor and a sixth inductor; the fifth inductor having a first end connected also to said second end of said fifth capacitor and having a second end connected to a third output terminal pin; and the sixth inductor having a first end connected also to said second end of said sixth capacitor and having a second end connected to a fourth output terminal pin.
14. An alarm filter circuit as claimed in claim 13 , wherein said first through fourth inductors and first through fourth capacitors function as the fourth-order elliptical low-pass filter section so as to block the DSL data signals to and from said alarm unit with a flatter response for frequencies between 25 KHz-100 KHz.
15. An alarm filter circuit as claimed in claim 13 , further comprising a seventh capacitor interconnected between the first end of said fifth capacitor and said first input terminal pin, an eighth capacitor interconnected between the first end of said sixth capacitor and said second input terminal pin, and a seventh inductor having its one end connected also to the first end of said fifth capacitor and having its other end connected also to the first end of said sixth capacitor so as to define a third-order high-pass filter section.
16. An alarm filter circuit as claimed in claim 13 , wherein said first through sixth inductors and first through sixth capacitors are housed in a modular type adaptor design having plug means on its one end for connection to the incoming telephone lines and having jack means on its other end for connection to said alarm unit.
17. An alarm filter circuit as claimed in claim 16 , wherein said plug means is a RJ-45 plug.
18. An alarm filter circuit as claimed in claim 17 , wherein said jack means is a RJ31X jack.
19. An alarm filter circuit as claimed in claim 18 , wherein said adapter design is capable of self-installation by a subscriber or customer.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
May 4, 2001
June 11, 2002
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